The height, h metres, of a flare as a function of the time, t seconds, since the flare was fired from a boat, can be modelled by the function h = -5t2 + 15t + 20 What was the maximum height of the flare?

31.25 metres at t=1.5 seconds.

Step-by-step explanation:

The height, h metres, of a flare as a function of the time, t seconds, since the flare was fired from a boat, can be modeled by the function

We need to find the maximum height of the flare.

In the given quadratic function, the leading coefficient is negative it means the function represents the downward parabola.

Vertex of a downward parabola is the point of maxima.

If a quadratic function is , then

In the given function, a=-5, b=15, c=20. So,

Put x=1.5 in the given function.

Therefore, the maximum height of the flare is 31.25 metres and t=1.5 seconds.

answer: ok

step-by-step explanation:

75 tickets have been sold so far.

step-by-step explanation:

in this question it is clearly mentioned that 45 children's tickets have been sold and this number is 60% of the total tickets sold.

now let's assume the total number of tickets sold be x.

then 60% of x = 45

⇒

⇒ x(.6) = 45

by dividing with .6 on both the sides of the equation

⇒ x = 75

therefore 75 tickets have been sold so far.